His name was Ivan Lopez and he came from Puerto Rico. He was married, had other family members and lived in the Fort Hood area, having arrived at the post in February from another military base in Texas. He was assigned to the 13th Sustainment Command (Expeditionary) at Fort Hood, which is a logistics and support unit. Officials did not release his rank on Wednesday, but said he was not in the process of leaving the Army.

Lopez served for four months in Iraq in 2011. Army Secretary John McHugh said Lopez did not see combat in Iraq. He was not wounded in action while serving overseas, but self-reported a traumatic brain injury upon his return to the US. “He was not a wounded warrior,” said Lt. Gen. Mark Milley, the senior officer at Fort Hood. “He was not wounded in action, to our records, no Purple Heart, not wounded in action in that regard.”

Lopez had several mental health issues. He was taking medication and receiving psychiatric help for depression and anxiety, and was undergoing a process to determine whether he had post-traumatic stress disorder. “We do not know a motive,” Milley said. “We do know that this soldier had behavioral health and mental health issues, and was being treated for that.”

Lopez had one weapon, a .45-caliber Smith & Wesson handgun, that was not registered with post authorities as required. Authorities don’t yet know how much ammunition he was carrying.

Lopez died from a self-inflicted gunshot wound. He killed himself in a parking lot at the base transportation brigade’s administration building after he was confronted by a military policewoman. “It was clearly heroic, what she did at that moment in time,” Milley said. “She did her job, and she did exactly what we would expect of United States Army military police.”